Some Investments by Jack Ma, Partners Were Made on Behalf of Alibaba or Funded by Loan From the Company

A series of deals involving Alibaba Group Holding Ltd. founder Jack Ma are raising red flags with corporate-governance experts and investors, as the Chinese Internet giant seeks to woo global money to a public offering that could be one of the largest in history.

In at least one case, Mr. Ma and a group of his allies have invested in a company on behalf of Alibaba through private vehicles. In other deals, a private-equity fund...